There is a Kelp which is processed so that it may be soluble in water and then one may use less, because then you have greater surface area availible because it is so fine!
But it cost a lot more, and I do not know if the cost ratio to effectiveness is any better than the fine powder which is available?
I prefer to buy the powder and "IF" I want it Liquid, then I buy the water soluble kind and make my own a lot cheaper!
I have both the fine powder which is sold for Human grade and the fine powder which is soluble in water for Foliar sprays on plants, but this which is for Foliar sprays is not sold for human use, but I think it could be used for it though!
The initial cost between the two is very Great, with the Maxicrop being the product for Foliar spray for Plants, being very much more costly than the powder for human use by the pound basis cost!
Smile Tis your choice.